How do I test and document seeds?

Changelog

To test and document seeds, use a schema file and nest the configurations under a seeds: key

Example:

data/schema.yml
version: 2
seeds:
- name: country_codes
description: A mapping of two letter country codes to country names
columns:
- name: country_code
tests:
- unique
- not_null
- name: country_name
tests:
- unique
- not_null